Field of the Invention
The present application relates to an exposure controller for an image sensor, a system including such a controller, a method for use in the controller and a computer program implementing the method.
Description of the Related Technology
An exposure controller is known for controlling the exposure of a plurality of dark pixels and of a plurality of bright pixels in an image sensor. The controller sets the exposure of the dark and bright pixels independently by determining the number of dark pixels that have a signal level below a ‘low’ threshold and the number of bright pixels that have a signal level above a ‘high’ threshold, respectively. The two partial images obtained by the dark and bright pixels are combined by adding signal levels of the corresponding dark and bright pixels to one merged pixel in a merged image with a large dynamic range.
If the known setting of the exposures is applied to a high dynamic range capture system involving multiple images captured sequentially in time, or involving alternation of exposure line by line as the sensor is scanned, the merged image may have a low quality.